Doctors urge younger adults to act on colorectal cancer symptoms

The American College of Surgeons is urging younger adults to seek care for possible colorectal cancer symptoms, as diagnoses have climbed in people below the usual screening age. The group says early attention to bowel changes, rectal bleeding and other warning signs can help patients get diagnosed while treatment is more likely to work.

The ACS has released free public education materials and a checklist meant to help patients prepare for primary care visits. The effort comes as colorectal cancer has become the leading cause of cancer-related death among people younger than 50, according to research cited by the ACS.

Routine screening for adults at average risk generally starts at 45, the U.S. Preventive Services Task Force recommends. The ACS says symptoms can appear before then, so age alone should not be used to dismiss new or continuing digestive problems.

Symptoms that warrant a doctor visit

The ACS checklist highlights several signs that can be easy to mistake for hemorrhoids, constipation or other common conditions. Marylise Boutros, a colorectal surgeon at Cleveland Clinic Florida who helped develop the materials, said younger patients’ bowel complaints are often treated conservatively, even as more young adults are being diagnosed.

• Ongoing constipation, diarrhea or a change from normal bowel habits
• Unusually narrow stools or a feeling that the bowel has not fully emptied
• Rectal pressure, discomfort or repeated bleeding
• Bright red, dark, tarry or mucus-containing stool
• Unexplained weight loss, fatigue, weakness, reduced appetite, nausea or vomiting

Paula Denoya, a colorectal surgeon at Stony Brook University Hospital and an ACS Commission on Cancer state chair, said such symptoms may come from noncancerous causes in younger patients. She said any bowel change that is new or unusual for that person should be raised with a health care provider, including during an annual wellness visit.

Bleeding draws particular concern

The ACS says repeated blood in the stool should be evaluated, even when the amount is small. Research presented at the ACS Clinical Congress 2025 found that among symptomatic patients younger than 50 who had colonoscopies, rectal bleeding was the strongest predictor of colorectal cancer and was tied to 8.5 times higher odds of diagnosis.

James T. McCormick, a colorectal surgeon at Allegheny Health Network and an ACS Commission on Cancer state chair, said bleeding is the most common colorectal cancer symptom but may also come from other conditions. He said recurring blood, whether seen on toilet paper, in the bowl or mixed with stool, may call for colonoscopy to identify the cause.

Risk and screening

The disease remains more common in older adults, and about 1 in 25 men and women will develop colorectal cancer during their lives, according to National Cancer Institute data cited by the ACS. The American Cancer Society says about 1 in 5 colorectal cancer cases now occurs in people younger than 54, compared with 11% three decades ago.

The ACS says some people may need screening before age 45, including those with a family history of colorectal cancer and those with inflammatory bowel diseases such as Crohn’s disease or ulcerative colitis. Several screening options exist, but the ACS describes colonoscopy as the gold standard because doctors can find cancer and remove precancerous polyps in the same procedure.

Boutros said colorectal cancer is highly treatable when found early and that surgical advances have made treatment less invasive. The ACS is encouraging patients to use its checklist to keep discussions with clinicians focused on concerning bowel changes.

This story draws on original reporting from ScienceDaily.